The Metabolic Physiology Shared Resource (MPSR) provides investigators with a platform for the design, execution, and interpretation of highly specialized procedures for conducting experiments in vivo. The MPSR facilitates research for investigators in the range of species spanning from mouse to humans. Many of the basic tenets of experimental design are species-Independent permitting resources and expertise to be pooled under the common MPSR umbrella. This philosophy alleviates experimental constraints by providing access to a variety of model systems and provides for seamless translation of basic experimental findings to humans. The impact and benefits of the MPSR are greater than the sum of Its constituent parts. The MPSR uses a defined mechanism for the design and optimization of experimental protocols using an established Studio format. The Studio (i) brings together Vanderbilt scientists with specific expertise to review a proposal; (ii) identifies potential limitations on the front-end; and (iii) leads to the most efficient use of resources including animals and human volunteers. The MPSR makes complex In vivo experiments feasible by providing specialized animal surgical (e.g. catheter placement, bariatric surgery) and experimental (e.g. clamps, energy balance) services. Advancements in the present cycle have led to the development of bariatric surgery procedures and expansion of resources for energy balance measurements In animals that parallel procedures used In human studies conducted by the MPSR. The MPSR has also added a human clamp component. The addition of these vital services fills out the scope of services leading to comprehensive analyses of insulin action and energy balance from rodents to large animals to human subjects. MPSR services will channel into analytical, statistical, and bioinformatics services, thereby enhancing the utility of this resource.